Pakistani health officials on Monday called for infants leaving the country to be issued polio vaccinations at airports after virus samples linked to a southern Pakistani city were discovered in Egypt.

Two sewage samples from Cairo were analysed and found to resemble a recently discovered strain in the city of Sukkur, a joint statement by health officials, the World Health Organization (WHO) and Unicef said.

“To reduce the possibility of spread of the polio virus beyond Pakistan’s borders, the government’s Monitoring and Coordination Cell is advising to set up permanent vaccination counters at the international departure lounges of all airports,” it said.

The statement recommended that “all children under five years leaving the country are vaccinated against the polio virus.”Though Egypt has been polio-free since 2004, authorities there have ordered the immediate vaccination of all children under five years of age in the areas where the samples were found.

Polio cases in Pakistan have risen sharply in recent years, hitting 198 in 2011, the highest figure for more than a decade and the most of any country in the world, according to the WHO.Unicef’s acting chief of polio unit, Michael Coleman said the incident highlighted the importance of vaccination in Pakistan.

“It reinforces the urgent need of all caregivers across Pakistan to vaccinate children under five years of age against polio through the nearest health facility or through campaign vaccination teams,” he said.Shahnaz Wazir Ali, the prime minister’s advisor on polio eradication, termed the case “a stark reminder of the risks associated with active polio virus transmission in the country.

Pakistan is one of only three countries where the highly infectious crippling disease remains endemic, along with Afghanistan and Nigeria.Earlier this month Pakistan provided paramilitary and police support to polio vaccination teams in the northwest after a series of attacks on medical workers.

UN agencies suspended work on a nationwide campaign to inoculate children against the highly infectious disease after nine health workers were murdered in a string of attacks in the northwest and Karachi in December last year.Rumours about the vaccine being a plot to sterilise Muslims have long dogged efforts to tackle the disease in Pakistan.Suspicion of vaccination programmes intensified after the jailing of a doctor who helped the CIA find Osama bin Laden in 2011 using a hepatitis campaign.